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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Phototransformation in air

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Administrative data

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Description of key information

Calculated photo-oxidation half lives ranging from 5.2 to 6.7 h for dipropylene glycol methyl ethers and 2 h for tripropylene glycol methyl ether are available.  Similarly, the corresponding measured half-life for methanol in the troposphere is 17 to 18 days.

Key value for chemical safety assessment

Half-life in air:
18 d

Additional information

The method of Atkinson (1987) was used with the EPIWIN program to estimate photo-oxidation half-lives based on reaction with hydroxyl radicals. Assuming a concentration of hydroxyl radicals of 1.5 X 10^6 molecules/cm3 and a 12h daylight period, a range of half-lives was calculated.

Half-lives for the di-propylene glycol ethers ranged from 5.2 to 7.6 h, averaging 6.5 h. The half-life for the tripropylene glycol methyl ether component is approximately 2 hours.

For the sodium methanolate component, complete conversion to sodium hydroxide and methanol in the environment is assumed. Methanol is moderately rapidly degraded by reaction with hydroxyl radicals with a measured rate constant of 9.44 x 10^-13 cm3/(molecules-sec). This correspondes to a half-life in the troposphere for methanol of 17 to 18 days.